摘要
根据国际计量局(BIPM)时间部和国内外一些实验室(USNO,CRL,TAO,CSAO,SO)的时间公报上公布的GPS时间比对数据,我们用三种方法(单站、飞越、共视)对GPS时间比对的时间测量精度和频率测量精度进行了比较分析,得到了如下一些结果。 1.最近三年(1989～1991)的GPS时间比对精度的平均值(数据取样时间为1天,按月单星计算结果后再多星结果平均,然后每年12个月平均)从40～60ns提高到20～30ns。 2.在实验室设备(接收机和钟)性能优良的条件下,1991年的GPS时间比对精度的结果是很好的:(1)单站法的结果为12.6～44.0ns,平均值为21.6ns;(2)飞越法的结果为14.4～33.8ns,平均值为18.5ns。(3)共视法的结果为7.7～25.4ns,平均值为13.5ns. 3.取样时间为1天和10天的GPS时间比对的频率测量精度分别为1～3×10-13和3～8×10-14.在频率稳定度模型中,取样时间为1～4天时的贡献主要是调频白噪声;取样时间为5～10天时的贡献主要是调频闪变噪声。
According to the data of GPS time comparison published by the time bulletin of BIPM time section and some laboratories in China and abroad (USNO, CRL, TAO, CSAO, SO), by using three methods (receiving at single station, flying over two station, common view between two stations), we carried out some comparison and analysis for the time measurement precision and the frequency measurement precision of GPS time comparison in this paper. Some results have been obtained as follows.
1. GPS time comparison precisions are similar indifferent laboratories, their average value's (the sampling time of data is one day. many satellite' s results were averaged when the single satellite's results was calculated every month, then the results of 12 months were averaged every year) have been improved from 40-60 ns to 20-30 ns.
2. Under the condition that the equipments (re'ceiver and clock) of the laboratory are best in quality, the results of GPS time comparison precision were very good in 1991. (1) the result of receiving at single station was 12.6-44.0 ns its average value was 21.6ns; (2) the result of receiving by flying over two stations were 14.4-33.8ns, its average value were 18.5 ns; (3) the result with common view between two stations were 7.7-26.4 ns, its average values were 13.6 ns.
3. The frequency measurement precision of GPS time comparison with sample time of 1 day and 10 days are respectively 1-3×10-13 and 3-8×10-14. In the model of frequency stability .The contribution with sample time of 1-4 days is mainly of white noise FM; the contribution with sample time of 5-10 days is mainly of flicker noise FM.
出处
《中国科学院上海天文台年刊》
1993年第14期281-293,共13页
Annals Shanghai Astronomical Observatory Chinese Academy of Sciences
